The Most Powerful Weapon in Your Spiritual Battles The Bible paints a vivid picture of an unseen but very real war going on in the heavens. Revelation 12:11 describes some of the weapons available to God's people for "fighting the good fight." The first weapon mentioned is Christ's blood. Do you know how to use this powerful weapon? Signed in His Blood explains the amazing relationship between Christ's blood and our covenant with God, bringing together both the Old and the New Testaments to demonstrate the incredible hope we have in Jesus for freedom and deliverance.